How to calculate the automatically some distance in the image based on the colour ?

Hello all, I am interested to calculate the automatically some distance in the image based on the colour. Is it possible to calculate the distance ? For example i want to calculate the Ha1 , Ha2 , Ha3 and Ha4 in the sample a , Hb1 , Hb2 , Hb3 and Hb4 in the sample b, Hc1 , Hc2 , Hc3 and Hc4 in the sample c, Hd1 , Hd2 , Hd3 and Hd4 in the sample d, He1 , He2 , He3 and He4 in the sample e

please find the general image and image to calculate the distance. I am not expert at MATLAB, but i am interested to learn this code. I will appreciate if any one tell me an code to perform this operation.

Thanks a ton

[KALYAN ACHARJYA]

Yes, possible, will update later.

[Kristen Chappel]

Thanks @KALYAN ACHARJYA, I will wait for your response.

[Image Analyst]

Do you want me or anyone else to do it for you? If so, see below in the "Answers" section.

[KALYAN ACHARJYA]

@Kristen Chappel Sorry, I was unable to response this question in due time. Now, you got a response from one among the best people @Image Analyst in image processing domain.

[Kristen Chappel]

@KALYAN ACHARJYA NO PROBLEM , I RECEVIED THE RESPONSE FROM IMAGE ANAYLYST AND HE EXPLAINED VERY WELL , BUT WAITING FOR THE MY LAST QUERY. YOU CAN CHECK MY LAST COMMENT AS WELL, IF INTERESTED TO SOLVE

Answer 1

[Image Analyst]

Kristen, try this:

% Demo by Image Analyst, February, 2021.
clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clearvars;
workspace;  % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 16;
fprintf('Beginning to run %s.m ...\n', mfilename);

%-----------------------------------------------------------------------------------------------------------------------------------
% Read in image.
folder = [];
baseFileName = 'General sample details 1.JPG';
fullFileName = fullfile(folder, baseFileName);
% Check if file exists.
if ~exist(fullFileName, 'file')
	% The file doesn't exist -- didn't find it there in that folder.
	% Check the entire search path (other folders) for the file by stripping off the folder.
	fullFileNameOnSearchPath = baseFileName; % No path this time.
	if ~exist(fullFileNameOnSearchPath, 'file')
		% Still didn't find it.  Alert user.
		errorMessage = sprintf('Error: %s does not exist in the search path folders.', fullFileName);
		uiwait(warndlg(errorMessage));
		return;
	end
end
rgbImage = imread(fullFileName);
[rows, columns, numberOfColorChannels] = size(rgbImage)
% Display the test image full size.
subplot(2, 2, 1);
imshow(rgbImage, []);
axis('on', 'image');
caption = sprintf('Original Image : "%s"', baseFileName);
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
hp = impixelinfo(); % Set up status line to see values when you mouse over the image.

% Set up figure properties:
% Enlarge figure to full screen.
hFig1 = gcf;
hFig1.Units = 'Normalized';
hFig1.WindowState = 'maximized';
% Get rid of tool bar and pulldown menus that are along top of figure.
% set(gcf, 'Toolbar', 'none', 'Menu', 'none');
% Give a name to the title bar.
hFig1.Name = 'Demo by Image Analyst';

%--------------------------------------------------------------------------------------------------------
% Threshold image.
grayImage = rgb2gray(rgbImage);
mask = grayImage < 100;
% Clean up the mask to get only hte 5 stripes we want.
% Get rid of blue surround
mask = imclearborder(mask);
% Take the 5 largest blobs.
mask = bwareafilt(mask, 5);
% Get rid of small tendrils
se = strel('disk', 2, 0);
mask = imopen(mask, se);

% Display mask image.
subplot(2, 2, 2);
imshow(mask, []);
axis('on', 'image');
title('Initial Mask', 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
hold on;
hp = impixelinfo(); % Set up status line to see values when you mouse over the image.

% Label each blob.
[labeledImage, numBlobs] = bwlabel(mask);
% For each blob, for each line, get the left edge and right edge then widths.
leftEdges = zeros(rows, 1);
rightEdges = zeros(rows, 1);
widths = zeros(rows, 5);
subplot(2, 2, 3:4);
hold on;
for blob = 1 : numBlobs
	thisBlob = ismember(labeledImage, blob);
	% Display mask image.
	subplot(2, 2, 2);
	imshow(thisBlob, []);
	axis('on', 'image');
	caption = sprintf('Mask of Blob #%d', blob);
	title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
	drawnow;
	hold on;
	hp = impixelinfo(); % Set up status line to see values when you mouse over the image.
	for row = 1 : rows
		thisRow = thisBlob(row, :);
		t = find(thisRow, 1, 'first');
		if ~isempty(t)
			leftEdges(row) = t;
			rightEdges(row) = find(thisRow, 1, 'last');
		end
	end
	widths(:, blob) = rightEdges - leftEdges;
	subplot(2, 2, 3:4);
	plot(widths, '-', 'LineWidth', 2);
	drawnow;
	legendStrings{blob} = sprintf('Blob #%d', blob);
end
grid on;
title('Widths', 'FontSize', fontSize, 'Interpreter', 'None');
xlabel('Row', 'FontSize', fontSize);
ylabel('Width in Pixels', 'FontSize', fontSize);
legend(legendStrings);

% Display mask image again.
subplot(2, 2, 2);
imshow(mask, []);
axis('on', 'image');
title('Mask', 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
hold on;
hp = impixelinfo(); % Set up status line to see values when you mouse over the image.

fprintf('Done running %s.m\n', mfilename);

By the way, don't use JPG format for image analysis if you can at all avoid it. Use PNG. JPG introduces artifacts that reduce your precision.

[Kristen Chappel]

HI @Image Analyst, THANK YOU SO MUCH, BUT RESULT DIDN'T CALCULATED THE VALUE, I WANTED TO CALCULATE AUTOMATICALLY THE MEAN AND STANDARD DEVIATION OF THE 5 RED MARKED RECTANGLE (RECTANCLE a , RECTANGLE b, RECTANGLE c , RECTANGLE d, AND RECTANGLE e) . SORRY I FORGET TO MARK THE SCALE IN THE PREVIOUS IMAGE AND DIDN'T DRAFT QUESTION VERY WELL.

JUST EXAMPLE IN THE RECTANGLE a ,

MEAN = (Ha1+Ha2+ Ha3+ Ha4+....+ Han)/ n

SIMILARLY STANDARD DEVIATION CACLULATION

BUT IT SHOULD CALCULATE AUTOMATICALLY , IS IT POSSIBLE? THANK YOU SO MUCH AND HAVE A NICE SUNDAY

[Image Analyst]

Kristen, it computes the widths everywhere. If you want it just at some particular row, then just use that row as an index in the array. Note that you did not tell us what row the H are at so there is no way I could have chosen some particular row.

But I don't know why those 4 rows are special or how they're found. Why not just get the average width over the entire stripe?

[Kristen Chappel]

@Image Analyst, THANKS FOR EXPLAINING ME.

1} YES BUT IT GIVES THE VALUE IN PIXEL , I WOULD LIKE TO KNOW THE VALUE IN MICRON . (SORRY IN THE QUESTION IMAGE, I FORGETED TO MENTION MICRO SCALE)

2}AS FAR AS I UNDERSTOOD, YOU MEAN THE CALCULATE ENTIRE STRIP BUT IT WON'T GIVE ACCURATE VALUE OF MEAN AND STANDARD DEVIATION. (AS STRIP DOESNOT START WITH ZERO). SO THATS THE REASON I CHOOSED 4 SPECIFIC POINT, BY THE WAY YOU CAN CHOOSE ANYWHERE IN THAT STRIP OR GIVE OPTION TO USER TO SELECT NUMBER OF MEASUREMENT AND POINT ON STRIP TO CALCULATE WIDTH AND THEN LATER CALCULATE THE MEAN AND STANDARD DEVIATION FOR THAT STRIP, IS IT POSSIBLE ? I WOULD APPRECIATE IF YOU EXPLAIN IT OR MODIFY YOUR DEMO CODE ACCORDING TO THAT. THANK YOU SO MUCH, BY THE WAY YOU EXPLAIN AND ANSWER VERY GOOD WAY. THANK YOU SO MUCH FOR THAT. HAVE A BEAUTIFUL SUNDAY.

[Kristen Chappel]

@Image Analyst, THANKS FOR EXPLAINING ME.

1} YES BUT IT GIVES THE VALUE IN PIXEL , I WOULD LIKE TO KNOW THE VALUE IN MICRON . (SORRY IN THE QUESTION IMAGE, I FORGETED TO MENTION MICRO SCALE)

2}AS FAR AS I UNDERSTOOD, YOU MEAN THE CALCULATE ENTIRE STRIP BUT IT WON'T GIVE ACCURATE VALUE OF MEAN AND STANDARD DEVIATION. (AS STRIP DOESNOT START WITH ZERO). SO THATS THE REASON I CHOOSED 4 SPECIFIC POINT, BY THE WAY YOU CAN CHOOSE ANYWHERE IN THAT STRIP OR GIVE OPTION TO USER TO SELECT NUMBER OF MEASUREMENT AND POINT ON STRIP TO CALCULATE WIDTH AND THEN LATER CALCULATE THE MEAN AND STANDARD DEVIATION FOR THAT STRIP, IS IT POSSIBLE ? I WOULD APPRECIATE IF YOU EXPLAIN IT OR MODIFY YOUR DEMO CODE ACCORDING TO THAT. THANK YOU SO MUCH, BY THE WAY YOU EXPLAIN AND ANSWER VERY GOOD WAY. THANK YOU SO MUCH FOR THAT. HAVE A BEAUTIFUL MONDAY

[Image Analyst]

Kristen, you totally misunderstood what I said. I was not saying that my suggestion would be inaccurate. I was saying that yours would be, if you just took only 4 lines to sample your widths at. Why would you think computing the widths from the entire length of the stripe would be less accurate than computing it from just 4 rows????

How about if you compute the mean and stddev for rows where the width is more than 30 pixels wide? Add on this code:

% Get the mean and stdev of widths where the width is more than 30 pixels.
for k = 1 : numBlobs
	thisWidth = widths(:, k);
	% Get indexes of those lines that are wide enough.
	indexes = thisWidth >= 30;
	meanWidths(k) = mean(thisWidth(indexes));
	stDev(k) = std(thisWidth(indexes));
	fprintf('For stripe #%d, the width = %.2f and standard deviation of widths = %.3f\n', ...
		k, meanWidths(k), stDev(k));
end

You get:

For stripe #1, the width = 51.71 and standard deviation of widths = 7.372

For stripe #2, the width = 62.57 and standard deviation of widths = 5.886

For stripe #3, the width = 63.84 and standard deviation of widths = 5.932

For stripe #4, the width = 65.97 and standard deviation of widths = 11.889

For stripe #5, the width = 43.95 and standard deviation of widths = 6.339

Note: this assumes the widths are all above 30 in the range you're interested in. If you might have widths dip below 30 in the middle of the stripe, then you migth want to include everything from where the width first gove aboe 30 to where it last drops below 30 like this:

for k = 1 : numBlobs
	thisWidth = widths(:, k);
	% Get indexes of those lines that are wide enough.
	index1 = find(thisWidth >= 30, 1, 'first');
	index2 = find(thisWidth >= 30, 1, 'last');
	meanWidths(k) = mean(thisWidth(index1 : index2));
	stDev(k) = std(thisWidth(index1 : index2));
	fprintf('For stripe #%d, the width = %.2f and standard deviation of widths = %.3f\n', ...
		k, meanWidths(k), stDev(k));
end

For stripe #1, the width = 51.71 and standard deviation of widths = 7.372

For stripe #2, the width = 62.48 and standard deviation of widths = 6.224

For stripe #3, the width = 63.84 and standard deviation of widths = 5.932

For stripe #4, the width = 65.61 and standard deviation of widths = 12.560

For stripe #5, the width = 42.91 and standard deviation of widths = 8.048

Basically there are lots of ways to define what row you want to start and stop on, and what rows to include in between. You could even just pick some rows, like between 100 and 600. But regardless, these ways of using many/most rows will be more accurate than simply taking only 4 rows.

[Anish Khan]

Hi @Image Analyst @Walter Roberson, I am adding my question to Kristen question because it is very similar to her. Can i calculate the mean and standard deviation for the attached image is it possible ? (I have attached the original image and other one attached to understand you that which value i need to calculate, (Black width, highlighted with the lime colour)) @KALYAN ACHARJYA@Jan

[Anish Khan]

Hi @Image Analyst @Walter Roberson, I am adding my question to Kristen question because it is very similar to her. Can i calculate the mean and standard deviation for the attached image is it possible ? (I have attached the original image and other one attached to understand you that which value i need to calculate, (Black width, highlighted with the lime colour)) @KALYAN ACHARJYA@Jan

[Image Analyst]

Yes, you can. It is possible. Just modify my code in the obvious ways to segment the image and check widths vertically instead of horizontally. It should be very straightforward.

[Anish Khan]

Hello @Image Analyst Thank you so much, i tried since the morning but It not works very well. Can you please modify the code ? Thank you in advance...

[Anish Khan]

Hi @Image Analyst It shows result like this, can you please modify your code according to my image ?

[Anish Khan]

Hi @Image Analyst I am stucked at the code, can you please modify your code according to my image ?

[Anish Khan]

Hi @Image Analyst I am still not able to solve your code, I would be very much thankful if you modify your code according to my image. Thank you so much

[Kristen Chappel]

Anish khan i tried but it shows the problem in my pc, I think this code is not suitable for your image. @Anish Khan. You can ask more to @Image Analyst

[Anish Khan]

Thanks Kristen even i tried since last complete day and night but facing a lot problem in the code. I don't know how to solve this problem, May be @Image Analyst knows how to change this code according to my image. I hope he will reply.

[Kristen Chappel]

Don't worry @Anish Khan, for sure you will get response from @Image Analyst. I am pretty sure that @Image Analyst can solve your problem.

[Anish Khan]

I don't know but @Image Analyst not yet replied. Probably he is busy in other task. I hope he will reply once he get free time.

[Image Analyst]

Yep, I do have a regular paying job that I work at 10-12 hours a day so sometimes I can't find time to help people. Here, try this and adapt as needed:

% Demo by Image Analyst, February, 2021.
clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clearvars;
workspace;  % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 16;
fprintf('Beginning to run %s.m ...\n', mfilename);

%-----------------------------------------------------------------------------------------------------------------------------------
% Read in image.
folder = [];
baseFileName = 'original image.JPG';
fullFileName = fullfile(folder, baseFileName);
% Check if file exists.
if ~exist(fullFileName, 'file')
	% The file doesn't exist -- didn't find it there in that folder.
	% Check the entire search path (other folders) for the file by stripping off the folder.
	fullFileNameOnSearchPath = baseFileName; % No path this time.
	if ~exist(fullFileNameOnSearchPath, 'file')
		% Still didn't find it.  Alert user.
		errorMessage = sprintf('Error: %s does not exist in the search path folders.', fullFileName);
		uiwait(warndlg(errorMessage));
		return;
	end
end
grayImage = imread(fullFileName);
[rows, columns, numberOfColorChannels] = size(grayImage)
if numberOfColorChannels == 3
	grayImage = rgb2gray(grayImage);
end
% Display the test image full size.
subplot(2, 3, 1);
imshow(grayImage, []);
axis('on', 'image');
caption = sprintf('Original Image : "%s"', baseFileName);
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
hp = impixelinfo(); % Set up status line to see values when you mouse over the image.

% Set up figure properties:
% Enlarge figure to full screen.
hFig1 = gcf;
hFig1.Units = 'Normalized';
hFig1.WindowState = 'maximized';
% Get rid of tool bar and pulldown menus that are along top of figure.
% set(gcf, 'Toolbar', 'none', 'Menu', 'none');
% Give a name to the title bar.
hFig1.Name = 'Demo by Image Analyst';

%--------------------------------------------------------------------------------------------------------
% Get histogram
subplot(2, 3, 2);
imhist(grayImage);
grid on;
xlabel('Gray Level', 'FontSize', fontSize);
ylabel('Count', 'FontSize', fontSize);

% Threshold image.
mask = grayImage < 75;
% Clean up the mask to get only the stripes we want.
mask(:, 1 : 762) = false;
mask(:, 2615 : end) = false;
% Get rid any blob not 1500 wide
labeledImage = bwlabel(mask);
props = regionprops(labeledImage, 'BoundingBox');
allBB = vertcat(props.BoundingBox);
widths = allBB(:, 3);
wideBlobs = find(widths > 1500);
% Extract only those that are wide enough.
mask = ismember(labeledImage, wideBlobs);

% Display mask image.
subplot(2, 3, 3);
imshow(mask, []);
axis('on', 'image');
title('Mask', 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
hold on;
hp = impixelinfo(); % Set up status line to see values when you mouse over the image.

% Label each blob with 8-connectivity, so we can make measurements of it
[labeledImage, numberOfBlobs] = bwlabel(mask, 8);
% Apply a variety of pseudo-colors to the regions.
coloredLabelsImage = label2rgb (labeledImage, 'hsv', 'k', 'shuffle');
% Display the pseudo-colored image.
subplot(2, 3, 4);
imshow(coloredLabelsImage);
title('Labeled Blobs', 'FontSize', fontSize, 'Interpreter', 'None');
% Get all the blob properties.  Can only pass in originalImage in version R2008a and later.
blobMeasurements = regionprops(labeledImage, grayImage, 'all');
numberOfBlobs = size(blobMeasurements, 1);

% For each blob, for each line, get the left edge and right edge then widths.
leftEdges = zeros(1, columns);
rightEdges = zeros(1, columns);
widths = zeros(columns, numberOfBlobs);
for blob = 1 : numberOfBlobs
	thisBlob = ismember(labeledImage, blob);
	% Display mask image.
	subplot(2, 3, 5);
	imshow(thisBlob, []);
	axis('on', 'image');
	caption = sprintf('Mask of Blob #%d of %d', blob, numberOfBlobs);
	title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
	drawnow;
	hp = impixelinfo(); % Set up status line to see values when you mouse over the image.
	for col = 1 : columns
		thisCol = thisBlob(:, col);
		t = find(thisCol, 1, 'first');
		if ~isempty(t)
			leftEdges(col) = t;
			rightEdges(col) = find(thisCol, 1, 'last');
		end
	end
	widths(:, blob) = (rightEdges - leftEdges)';
	subplot(2, 3, 6);
	plot(widths, '-', 'LineWidth', 1);
	hold on;
	grid on;
	drawnow;
	legendStrings{blob} = sprintf('Blob #%d', blob);
end
grid on;
title('Widths', 'FontSize', fontSize, 'Interpreter', 'None');
xlabel('Row', 'FontSize', fontSize);
ylabel('Width in Pixels', 'FontSize', fontSize);
legend(legendStrings);

% Display mask image again.
subplot(2, 3, 5);
imshow(mask, []);
axis('on', 'image');
title('Mask', 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
hold on;
hp = impixelinfo(); % Set up status line to see values when you mouse over the image.

fprintf('Done running %s.m\n', mfilename);

[Anish Khan]

Thanks @Image Analyst

[Image Analyst]

Give me a generic image with horizontal stripes that I can replace it with. Make sure the script works with it before you attach the image.

[Image Analyst]

You didn't try it and of course it didn't work. So I created a generic image of blurry stripes of slightly varying widths. No one will be able to tell what it is, especially with the aliasing going on when it's subsampled for display. It's just a bunch of stripes.

% Demo by Image Analyst, March, 2021.
clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clearvars;
workspace;  % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 16;
fprintf('Beginning to run %s.m ...\n', mfilename);

%-----------------------------------------------------------------------------------------------------------------------------------
% Read in image.
folder = [];
baseFileName = 'original image3.JPG';
fullFileName = fullfile(folder, baseFileName);
% Check if file exists.
if ~exist(fullFileName, 'file')
	% The file doesn't exist -- didn't find it there in that folder.
	% Check the entire search path (other folders) for the file by stripping off the folder.
	fullFileNameOnSearchPath = baseFileName; % No path this time.
	if ~exist(fullFileNameOnSearchPath, 'file')
		% Still didn't find it.  Alert user.
		errorMessage = sprintf('Error: %s does not exist in the search path folders.', fullFileName);
		uiwait(warndlg(errorMessage));
		return;
	end
end
grayImage = imread(fullFileName);
[rows, columns, numberOfColorChannels] = size(grayImage)
if numberOfColorChannels == 3
	grayImage = rgb2gray(grayImage);
end
% Display the test image full size.
subplot(2, 3, 1);
imshow(grayImage, []);
axis('on', 'image');
caption = sprintf('Original Image : "%s"', baseFileName);
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
hp = impixelinfo(); % Set up status line to see values when you mouse over the image.

% Set up figure properties:
% Enlarge figure to full screen.
hFig1 = gcf;
hFig1.Units = 'Normalized';
hFig1.WindowState = 'maximized';
% Get rid of tool bar and pulldown menus that are along top of figure.
% set(gcf, 'Toolbar', 'none', 'Menu', 'none');
% Give a name to the title bar.
hFig1.Name = 'Demo by Image Analyst';

%--------------------------------------------------------------------------------------------------------
% Get histogram
subplot(2, 3, 2);
imhist(grayImage);
grid on;
xlabel('Gray Level', 'FontSize', fontSize);
ylabel('Count', 'FontSize', fontSize);

% Threshold image.
mask = grayImage < 75;
% Clean up the mask to get only the stripes we want.
mask(:, 1 : 762) = false;
mask(:, 2615 : end) = false;
% Get rid any blob not 1500 wide
labeledImage = bwlabel(mask);
props = regionprops(labeledImage, 'BoundingBox');
allBB = vertcat(props.BoundingBox);
widths = allBB(:, 3);
wideBlobs = find(widths > 1500);
% Extract only those that are wide enough.
mask = ismember(labeledImage, wideBlobs);

% Display mask image.
subplot(2, 3, 3);
imshow(mask, []);
axis('on', 'image');
title('Mask', 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
hold on;
hp = impixelinfo(); % Set up status line to see values when you mouse over the image.

% Label each blob with 8-connectivity, so we can make measurements of it
[labeledImage, numberOfBlobs] = bwlabel(mask, 8);
% Apply a variety of pseudo-colors to the regions.
coloredLabelsImage = label2rgb (labeledImage, 'hsv', 'k', 'shuffle');
% Display the pseudo-colored image.
subplot(2, 3, 4);
imshow(coloredLabelsImage);
title('Labeled Blobs', 'FontSize', fontSize, 'Interpreter', 'None');
% Get all the blob properties.  Can only pass in originalImage in version R2008a and later.
blobMeasurements = regionprops(labeledImage, grayImage, 'all');
numberOfBlobs = size(blobMeasurements, 1);

% For each blob, for each line, get the left edge and right edge then widths.
leftEdges = zeros(1, columns);
rightEdges = zeros(1, columns);
widths = zeros(columns, numberOfBlobs);
for blob = 1 : numberOfBlobs
	thisBlob = ismember(labeledImage, blob);
	% Display mask image.
	subplot(2, 3, 5);
	imshow(thisBlob, []);
	axis('on', 'image');
	caption = sprintf('Mask of Blob #%d of %d', blob, numberOfBlobs);
	title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
	drawnow;
	hp = impixelinfo(); % Set up status line to see values when you mouse over the image.
	for col = 1 : columns
		thisCol = thisBlob(:, col);
		t = find(thisCol, 1, 'first');
		if ~isempty(t)
			leftEdges(col) = t;
			rightEdges(col) = find(thisCol, 1, 'last');
		end
	end
	widths(:, blob) = (rightEdges - leftEdges)';
	subplot(2, 3, 6);
	plot(widths, '-', 'LineWidth', 1);
	hold on;
	grid on;
	drawnow;
	legendStrings{blob} = sprintf('Blob #%d', blob);
end
grid on;
title('Widths', 'FontSize', fontSize, 'Interpreter', 'None');
xlabel('Row', 'FontSize', fontSize);
ylabel('Width in Pixels', 'FontSize', fontSize);
legend(legendStrings);

% Display mask image again.
subplot(2, 3, 5);
imshow(mask, []);
axis('on', 'image');
title('Mask', 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
hold on;
hp = impixelinfo(); % Set up status line to see values when you mouse over the image.

fprintf('Done running %s.m\n', mfilename);

[EDIT, unidentifiable image and screenshot replaced by a different unidentifiable image that I completely synthesized with a custom script, and replaced the screenshot as well, at the request of Mehbuba.]

[Image Analyst]

@Kristen Chappel, sorry your thread has been hijacked by this...

@Mehbuba Shaikh, I made a script, test5.m, to completely synthesize an image of horizontal stripes that no one on earth could possibly say that it has anything to do with your original images because I made it myself out of nothing but just the cos() and linspace() of MATLAB. It's just a completely generic arbitrary image of wavy stripes. No more changes, okay?

% Demo by Image Analyst, February, 2021.
clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clearvars;
workspace;  % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 16;
fprintf('Beginning to run %s.m ...\n', mfilename);

%-----------------------------------------------------------------------------------------------------------------------------------
% Read in image.
folder = [];
baseFileName = 'original image3.JPG';
fullFileName = fullfile(folder, baseFileName);
% Check if file exists.
if ~exist(fullFileName, 'file')
	% The file doesn't exist -- didn't find it there in that folder.
	% Check the entire search path (other folders) for the file by stripping off the folder.
	fullFileNameOnSearchPath = baseFileName; % No path this time.
	if ~exist(fullFileNameOnSearchPath, 'file')
		% Still didn't find it.  Alert user.
		errorMessage = sprintf('Error: %s does not exist in the search path folders.', fullFileName);
		uiwait(warndlg(errorMessage));
		return;
	end
end
grayImage = imread(fullFileName);
[rows, columns, numberOfColorChannels] = size(grayImage)
if numberOfColorChannels == 3
	grayImage = rgb2gray(grayImage);
end
% Display the test image full size.
subplot(2, 3, 1);
imshow(grayImage, []);
axis('on', 'image');
caption = sprintf('Original Image : "%s"', baseFileName);
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
hp = impixelinfo(); % Set up status line to see values when you mouse over the image.

% Set up figure properties:
% Enlarge figure to full screen.
hFig1 = gcf;
hFig1.Units = 'Normalized';
hFig1.WindowState = 'maximized';
% Get rid of tool bar and pulldown menus that are along top of figure.
% set(gcf, 'Toolbar', 'none', 'Menu', 'none');
% Give a name to the title bar.
hFig1.Name = 'Demo by Image Analyst';

%--------------------------------------------------------------------------------------------------------
% Get histogram
subplot(2, 3, 2);
imhist(grayImage);
grid on;
xlabel('Gray Level', 'FontSize', fontSize);
ylabel('Count', 'FontSize', fontSize);
title('Histogram of Gray Scale Image', 'FontSize', fontSize, 'Interpreter', 'None');

% Threshold image.
mask = grayImage < 75;
% Clean up the mask to get only the stripes we want.
mask(:, 1 : 762) = false;
mask(:, 2615 : end) = false;
% Get rid any blob not 1500 wide
labeledImage = bwlabel(mask);
props = regionprops(labeledImage, 'BoundingBox');
allBB = vertcat(props.BoundingBox);
widths = allBB(:, 3);
wideBlobs = find(widths > 1500);
% Extract only those that are wide enough.
mask = ismember(labeledImage, wideBlobs);

% Display mask image.
subplot(2, 3, 3);
imshow(mask, []);
axis('on', 'image');
title('Mask', 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
hold on;
hp = impixelinfo(); % Set up status line to see values when you mouse over the image.

% Label each blob with 8-connectivity, so we can make measurements of it
[labeledImage, numberOfBlobs] = bwlabel(mask, 8);
% Apply a variety of pseudo-colors to the regions.
coloredLabelsImage = label2rgb (labeledImage, 'hsv', 'k', 'shuffle');
% Display the pseudo-colored image.
subplot(2, 3, 4);
imshow(coloredLabelsImage);
caption = sprintf('%d Labeled Blobs', numberOfBlobs);
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
% Get all the blob properties.  Can only pass in originalImage in version R2008a and later.
blobMeasurements = regionprops(labeledImage, grayImage, 'all');
numberOfBlobs = size(blobMeasurements, 1);

% For each blob, for each line, get the left edge and right edge then widths.
leftEdges = zeros(1, columns);
rightEdges = zeros(1, columns);
widths = zeros(columns, numberOfBlobs);
for blob = 1 : numberOfBlobs
	thisBlob = ismember(labeledImage, blob);
	% Display mask image.
	subplot(2, 3, 5);
	imshow(thisBlob, []);
	axis('on', 'image');
	caption = sprintf('Mask of Blob #%d of %d', blob, numberOfBlobs);
	title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
	drawnow;
	hp = impixelinfo(); % Set up status line to see values when you mouse over the image.
	for col = 1 : columns
		thisCol = thisBlob(:, col);
		t = find(thisCol, 1, 'first');
		if ~isempty(t)
			leftEdges(col) = t;
			rightEdges(col) = find(thisCol, 1, 'last');
		end
	end
	widths(:, blob) = (rightEdges - leftEdges)';
	subplot(2, 3, 6);
	plot(widths, '-', 'LineWidth', 1);
	hold on;
	grid on;
	drawnow;
	legendStrings{blob} = sprintf('Blob #%d', blob);
end
grid on;
title('Widths', 'FontSize', fontSize, 'Interpreter', 'None');
xlabel('Row', 'FontSize', fontSize);
ylabel('Width in Pixels', 'FontSize', fontSize);
legend(legendStrings, 'Location', 'south');

% Display mask image again.
subplot(2, 3, 5);
imshow(mask, []);
axis('on', 'image');
title('Mask', 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
hold on;
hp = impixelinfo(); % Set up status line to see values when you mouse over the image.

fprintf('Done running %s.m\n', mfilename);

[Image Analyst]

See my attached spatial calibration demo.

[Mehbuba Shaikh]

Thanks a lot but i am not figuring out how to use this code in this script to indciate dimension in mm instead of the pixel @Image Analyst

[Image Analyst]

Let's not continue to hijack @Kristen Chappel's question and bug her. Start your own question and we'll continue on there where I'll show you that you can simply do distanceInMm = distanceInPixels * mmPerPixel.

[Mehbuba Shaikh]

You are right, i have created the question @Image Analyst

[Mehbuba Shaikh]

here is the question link How to measure distance in mm instead of pixel ? - MATLAB Answers - MATLAB Central (mathworks.com)

Answer 2

[Jenny Lee]

I am using more or less similar image like uploaded by anish khan, but this code not worked for me. @Image Analyst Could you please change your code to according to the Anish Khan image?

[Image Analyst]

@Jenny Lee start your own question with your own image and own code and I'll try to fix it.